Re: [PATCH v3 13/13] tty: serial: qcom-geni-serial: add support for serial engine DMA

Bartosz Golaszewski
2022-11-29T10:14:42Z

On Fri, Nov 25, 2022 at 3:37 PM Srinivas Kandagatla
<srinivas.kandagatla@linaro.org> wrote:
>

[snip]

> > +
> > +static void qcom_geni_serial_start_tx_dma(struct uart_port *uport)
> > +{
> > + struct qcom_geni_serial_port *port = to_dev_port(uport);
> > + struct circ_buf *xmit = &uport->state->xmit;
> > + unsigned int xmit_size;
> > + int ret;
> > +
> > + if (port->tx_dma_addr)
> > + return;
> Is this condition actually possible?
>

So it turns out, it's possible that the subsystem calls start_tx when
this is already set but the main engine is not yet in active state (so
we can't simply test that bit). This needs to stay then.

Bart